Portable piano



Sept. 1, 1964 G. s. MANDY ETAL PORTABLE PIANO 2 Sheets-Sheet 1 Filed NOV. 20, 1962 GAYLOIZB G. MANDY RuDv E. 6/574.

INVENTORS ATTOIZNE-VS p 1, 1964 G. G. MANDY ETAL 3,146,658

PORTABLE PIANO Filed NOV. 20, 1962 2 Sheets-Sheet 2 k\ 4| -Fl F1 F1 H G A VLOED G MANDY Ruov E. GIETL G 6 IN VEN TORS ATTORNEYS United States Patent 3,146,658 PORTABLE PIANO Gaylord G. Mandy, 316 Maryland St., and Rudy E. Gietl,

521 E. Oak Ave., both of El Segundo, Calif.

Filed Nov. 20, 1962, Ser. No. 238,852 3 Claims. (Ql. 84-177) This invention has to do with pianos and particularly with small-sized, portable pianos.

An object of the invention is to provide a novel, compact, relatively small portable piano. Also it is an object to provide such a piano having a full-sized keyboard so constructed that it can be folded or partially collapsed when not in use.

Another object is to provide a novel hammer action for a piano which is electromagnetically controlled and actuated.

A further object is to provide a novel, relatively small, music wire or piano string mounting frame together with a novel, compact arrangement of hammer assemblies associated therewith.

Another object is to provide a novel hammer action for pianos and the like.

Still another object is to provide a piano which can be manufactured at relatively low cost.

These and other objects will be apparent from the drawings and the following description. drawings:

FIG. 1 is a perspective view of a piano embodying the invention shown open and ready or use;

FIG. 2 is a view similar to FIG. 1 but showing the piano closed for storage or transport;

FIG. 3 is a sectional elevational view through the piano of FIG. 1 on line 33 thereof, but on a larger scale;

FIG. 4 is a fragmentary sectional view in the plane of FIG. 3 with the keyboard retracted and the cover closed;

FIG. 5 is a fragmentary side elevational view of a typical piano key and a cross sectional view of the supporting shelf therefor;

FIG. 6 is a fragmentary sectional view on line 6--6 of FIG. 5;

FIG. 7 is an elevational view of one leg, on a larger scale;

FIG. 8 is a fragmentary sectional view in a plane similar to that of FIG. 3 and showing a hammer and damper assembly in elevation;

FIG. 9 is a fragmentary elevational view on line 99 of FIG. 8;

FIG. 10 is a fragmentary sectional view on line 10-10 of FIG. 9;

FIG. 11 is an enlarged fragmentary sectional view of one end portion of the keyboard retracted within the case;

FIG. 12 is a partial end view of the device showing the bracket for supporting the keyboard;

FIG. 13 is a detail sectional view of one damper; and

FIG. 14 is a face view of the string assembly.

More particularly describing the invention, numeral 11 generally designates the case or housing of the piano and this includes a front wall 12, rear wall 13, lower or bottom wall 14, end walls 15 and top wall 16. The latter embodies a hinged cover section 16A which is shown open in FIGS. 1 and 3 and closed in FIGS 2 and 4. ,R'.A suitable handle 17 is provided on the top wall to the rear of the cover. The end walls are provided with door panels 20 each of which is hingedly mounted along its rear edge 21.

The case also is provided with four legs 23 and preferably these are so mounted that they can be retracted into Referring to the the case. Each leg may telescope within a mounting tube 24 secured to an end wall of the case and be provided with a pin 25 which is received in a slot 26 in the tube having offset end portions 26a and 26b so that the leg can be selectively positioned.

The keyboard, which is generally designated by numeral 30, includes a shelf 31 supported upon brackets 32 on the front wall of the case in any desired manner such that it can be moved transversely forwardly and rearwardly of the case to position it forward for playing as shown in FIGS. 1 and 3, or retracted as shown in FIG. 4. A detent mechanism (not shown) can be used to releasably lock the shelf in position. In this connection, the shelf 31, which is preferably as long as a full-length piano keyboard and longer than the case 11, is divided into a central section 31A and two end sections 31B which are attached thereto by hinges 33. It will be seen that these end portions 313 can be pivoted to hang vertically downward within the case (FIG. 11) with the keyboard retracted and thus permit of the door panels 20 being closed. When the ends 31B are extended they are supported by Y-shaped braces 34 which include a hinged joint 35 which limits pivotal movement of the parts to a position just over center as in FIG. 1. Each bracket is hingedly mounted at 36 on an end 31B of the shelf 31.

Carried on the shelf 31 are white keys 40 and black keys 41 of conventional size, number and arrangement. These keys are pivotally mounted upon a rod 42 which is supported upon a plurality of posts 43 mounted on shelf 31. The downward movement of each key is limited by a resilient washer 44 at the base of a guide pin 45 received in a bore 46 in the key, the latter being lined with a resilient material 47. A spring 50 is provided between each key and the shelf 31 to resist downward movement of the key and to return it to its original position.

The hammer action, which will later be described, is electromagnetically operated and consequently each key, when depressed, is made to close a circuit through an electromagnet and for this purpose each key is provided with a contact 52 which, when the key is depressed, engages a terminal or contact 53 carried by the shelf, the two contacts being connected in series in the circuit with the electromagnet.

Mounted within the case we provide a music wire or string assembly designated generally 55 and associated with this a bank of hammers 56 and hammer actuating mechanisms 58. The string assembly includes a metal harp or frame 60 having parallel ends 61 and 62 extending between sides 63 and 64 (FIG. 14). A plurality of reinforcement cross member 64' are provided between the sides. Strings 65 are secured at one end to hitch pins 66 in side 64 of the frame and secured about sets of tuning pins 67 at the opposite side 63. In the interests of lightweight and strength, the harp 60 may be a casting of a high strength aluminum alloy such as that known in the trade as 35 6-T6. The frame is backed by a sounding board frame 70 having a sounding board 71, and a bridge 72 is provided between the sounding board and the strings. Any suitable means may be used for mounting the string assembly in the case.

The hammer action or mechanism is mounted upon an upright stationary supporting wall 75 which extends from end to end of the case. Each hammer comprises an elongated body 78 with inclined end portions 80 and 81, the former being fitted with a cushioned head 83. Each hammer is pivotally mounted in a bushing portion 84 thereof on a rod 85 carried on a plurality of supports 86. The hammers normally lie against a cushioned rest bar 88.

The end 81 of each hammer is apertured to receive a string of metal, nylon or other suitable material by means of which the hammer is connected to a vertically movable armature or actuator 92, the string passing through a hole therein at its upper end and being knotted or otherwise secured at each end. Associated with each armature or actuator is an electromagnet 98 which is positioned below theactuator upon wall 75 and is connected with a source of direct current in a circuit which is closed upon depressing one of the piano keys by the closing of the switch associated with the key. The electromagnets are staggered as shown in FIG. 9 in the interests of a compact design and the lengths of the actuators are varied accordingly.

The armatures 92 are made of a suitable magnetic or magnetically sensitive sheet metal and each is provided with a slot 100 which freely receives a retaining pin 101 carried by the wall 75. Each member 92 has a head 92' adjacent its electromagnet. Only the head need be magnetic.

A plurality of damper members each of which comprises a rod 105 having a pad 106 at its inner end are mounted in wall 75, the damper rods being axially movable in bushings 107 therein. A spring 108 serves to hold the damper against its associated string. Each damper is retracted by the action of the armature through the medium of a string 110 connected thereto and to the end of the damper rod, the string passing around a pulley 111. Thus each hammer and its associated damper are actuated simultaneously. 1

In view of the fact that the piano is relatively small, to insure volume of sound and quality, we prefer to utilize an electronic sound pickup, amplification and reproduction means, and this has been diagrammatically indicated by the sound pickup elements 115, the amplifier 116 and the speaker 117. Since such equipment is Well known, it is unnecessary to show or describe any details thereof. A fabric-covered opening 118 is shown provided in the front wall of the case for the emission of sound from the speaker. t I

If desired, the piano may also be provided with a foot pedal and connecting linkage (not shown) for simultaneously retracting the dampers. To accomplish this, the dampers may be slotted at 120 to receive a bar 121 designed to be mounted for lateral movement toward wall 75 when retracted by suitable means;

Although we have illustrated and described a preferred form of our invention, we contemplate that various changes and modifications can be made therein without departing from the invention, the scope of which is indicated by the following claims.

4: We claim: 1. In a piano, a case, a sectional keyboard including 'a central section and hingedly attached end sections,

means for holding said end sections in position to form planar extensions of said central section, the over-all length of said keyboard exceeding that'of the case with the end sections extended, said end sections being sufficiently long and being swingable toward said central section to reduce the over-all length of the keyboard and thereby permit the same to be received in said case, and means mounting said central section in said case.

2. In a piano, a case, a keyboard including a keysupporting shelf and keys movably mounted thereon, means supporting said shelf in said case, said shelf including a center section and two end sections hingedly connected thereto adapted either to form a planar continuation of said center section or to be pivoted to depend therefrom, said keyboard being longer than said case with said end sections extended and being receivable in the case with the. end sections depending, said keyboard being transversely movable from a position within the case to a position extending forwardly of the case, and means forming part of the case for enclosing said keyboard when the ends are depending.

3. In a piano, a case having a top wall, front and rear walls, a bottom wall, and end walls, an-upwardly pivotable cover section forming the forward part of the top wall, an end panel on each end wall hinged to pivot out and rearwardly, said panels being located at the forward upper corners of the ends, a piano keyboard including a central section mounted in the case at the upper forward portion thereof beneath said cover and supported to be moved forward and partially out of the case, said keyboard including hingedly mounted end sections adapted to be positioned as planar extensions of said central section and adapted to swing downwardly and depend therefrom, and means'for bracing said end sections in upper position.

References Cited in the file of this patent UNITED STATES PATENTS Rogers Mar. 5, 1872 426,332 Sc'haaf Apr. 22, 1890 a 878,926 Ziegler Feb. 11, 1908 2,470,674 Zaiser May 17, 1949 2,487,420 Brown Nov. 8, 1949 2,532,070 Moore et al. Nov. 28, 1950 2,947,210, Facey et al. Aug. 2, 1960 .FOREIGN PATENTS 446,351 Great Britain n, Apr. 29, 1936 

1. IN A PIANO, A CASE, A SECTIONAL KEYBOARD INCLUDING A CENTRAL SECTION AND HINGEDLY ATTACHED END SECTIONS, MEANS FOR HOLDING SAID END SECTIONS IN POSITION TO FORM PLANAR EXTENSIONS OF SAID CENTRAL SECTION, THE OVER-ALL LENGTH OF SAID KEYBOARD EXCEEDING THAT OF THE CASE WITH THE END SECTIONS EXTENDED, SAID END SECTIONS BEING SUFFICIENTLY LONG AND BEING SWINGABLE TOWARD SAID CENTRAL SECTION TO REDUCE THE OVER-ALL LENGTH OF THE KEYBOARD AND THEREBY PERMIT THE SAME TO BE RECEIVED IN SAID CASE, AND MEANS MOUNTING SAID CENTRAL SECTION IN SAID CASE. 